Pinch bar mechanism for bag machines



@cct l, 135., G. W. POPPE PINCH BAR MECHANISM FOR BAG MACHINES Original Filed Sept. 50, 1932 3 Sheets-Sheet 1 Enventor GEORGE W- P PE (Ittorneg Um. L 19350 G. w. POPPE PINCH BAR MECHANISM FOR BAG MACHINES Original Filed Sept. 30, 1932 3 Sheets-Sheet 2 I Snnentor GEORGE w. POPPE fiw/ (Ittorneg Nv wm mw I 3 I mm ha mm. w J em a. T.\%

wm wm G. W. POPPE PINCH BAR MECHANISM FOR BAG MACHINES Original Filed Sept. 30, 1952' 5 Sheets-Sheet 3 GEORGE W POPPE wwg (Ittorneg Patented Oct. 1, 1935 PATENT OFFICE PINCH BAR MECHANISM FOR BAG MACHINES George W. Poppe, Brooklyn, N. Y., assignor to Equitable Paper Bag 00., Inc., Brooklyn, N. Y., a corporation of New York Original application September 30, 1932, Serial No. 635,533. Divided and this application June 21, 1933, Serial No. 676,873

4 Claims.

This invention relates to a machine for making bags and more particularly for making bags from relatively thin material. The improvements, however, are not limited to a machine for handling thin material but possess advantages when making bags of ordinary paper.

This application is a division of my application Serial No. 635,533, filed September 30, 1932.

An object of the invention is the better control and handling of the bag material. A feature of the invention relates to the provision of a central bearing for the upper pinch bar shaft whereby the pinch bar carried thereby will perform its function in a more reliable manner notwithstanding the vibrations to which the shaft is subjected during the severance of the bag tube.

Another feature of the invention relates to the provision of means whereby the pinch bar shafts and striker bar or bars may be more accurately and conveniently adjusted inproper timed relation.

Other features and advantages will become apparent from the following description and claims when taken in connection with the accompanying drawings in which:-

Figure 1 is a longitudinal section of a bag machine embodying my improvements;

Figure 2 is a plan in part sectional view on the line 2-2, Figure 1;

Figure 3 is a sectional view on the line 33, Figure 1;

Figure 4 is a section on the line 4-4, Figure 3; and

Figure 5 is a section on the line 55, Figure 3.

Referring to the drawings and more particularly to Figures 1 and 2 there is the usual supporting framework 2, the side members of which carry the various shafts for driving the usual mechanism of a bag machine, together with brackets for supporting the various auxiliary structures with which the present invention is more particularly concerned.

Referring to Figure 2, the machine is driven from a motor 4 whose shaft is provided with a pulley 5 about which passes a belt 5 to a pulley l on the shaft 8, which carries the lower pinch roller and from which shaft most of the other parts receive their drive. On this shaft is also carried a sprocket wheel 5, Figure 3, over which passes a sprocket chain is connected to a sprocket l l on shaft I 2, Figures 2 and 3. A tension roller i3 is provided to keep the sprocket chain sufficiently taut. The shaft i2 carries a gear that meshes with a similar gear on a stud shaft I l. The latter shaft carries a sprocket wheel for engagement with a sprocket chain l 5 by which motion is transmitted to shaft [6.

The paper or other material which is to form the bags is fed as a web l8 from a roll I!) supported on a shaft 20 in the lower portion of the rear 5 framework. The web passes over guide rollers 22, 23 and 24 and around another roller 26 which reverses its direction of movement, the latter roller being carried by shaft 21.

The mechanism so far described is that which 10 is found in an ordinary bag machine. In order to properly control a web of thin material the roller 26 is preferably positively driven. The details of this construction, however, form no part of the present invention but are made the 15 subject matter of a separate application and will therefore not be further described.

The paper web after passing over the roller 26 is delivered to mechanism which folds it into the bag tube in the usual manner, such mecha- 20 nism including a former plate 38, the right end of which, as indicated in Figure 1, is bent upwardly at about The former is supported from a I bridge 40 carried by arms 4| projecting forwardly and upwardly. The web passes under the former and is folded over onto it as illustrated in Figure 2. Projecting upwardly from the side plates 2 are four standards 42 which support two plates 43, Figure 2, the plates being separated sufficiently to permit the bag tube to freely move between them. Adjustment of the plates to and from each other is effected by slotting the plates as shown in Figure 2 and providing set screws to hold them in the proper adjustment. These plates 43 support rollers which aid in giving the 35 necessary control of the folded web and will be referred to later in greater detail.

The folded tube passes to the feed rollers indicated at 44, the upper pair of which are mounted on shaft 45 and the lower pair on shaft 55, 40 these shafts extending into and being supported by the side frames of the machine. Preferably the upper rollers are provided with facings 44a of rubber, leather or other material such as will provide the desired surface friction. The lower 45 rollers are of steel without facings. For driving the feed rollers there is provided a gear 48 on the shaft 8, Figures 2 and 3, which gear meshes with an idler 50 which in turn meshes with a gear 5| on the lower shaft 46. Near its other 50 end but within the frame 2 the shaft 46 carries gear 52 meshing with gear 53 on the upper shaft 45. The gears 52 and 53 are of the same size so that the feed rollers rotate in a 1 to 1 ratio.

After the web has been formed into a bag tube by being folded over the former and passes between the feed rollers 44 it is severed into a bag length by mechanism including the so-called pinch bars and the striker bar. The pinch bars are also driven from the shaft 8 which has secured to it a pinion 55 meshing with a pinion 56 on the upper shaft 54 which carries the pinch bar ll, the pinions 55 and 56 also driving in 2.

1 to 1 ratio.

After the severance of the bag tube it'passes lower cylinders carrying respectively a tucker blade and clamp, which cylinders are likewise driven from the shaft 8. For this purpose said shaft carries a gear 51, Figure 3, meshing with an idler gear 58 carried by a stud shaft. The latter gear meshes with gear 60 on the lower cylinder ,62 which is geared in a 1 to 1 ratio with the upper cylinder 64 carrying the tucker blade which blade is not shown but which is of the usual and well known construction.

The bag tube is severed by striker bar mechanism, which mechanism in the present instance has been somewhat modified in order to make it easier to accurately adjust the striker bars. This mechanism is constructed as,fo11ows: carried by the side frames 2 is a shaft 66 supporting a hub 6i having formed integral therewith two sprocket members 68. Supported by standards In, one on each side of the machine, is a shaft 12 which carries sprockets corresponding to the sprockets 68 and about which pass two chains I3, one on each side of the machine, between which the striker bars I4 and I5 extend.

The hub 61 has a slot milled into it near its central portion as indicated by the shading in Figure 3, which slot extends through the hub'to the central bore and a bolt II passes through holes near the center as shown more particularly in Figure 5. By tightening up on the bolt the hub is clamped tightly to the shaft 66. The shaft 66 is driven from the shaft 8 through gear 51, idler I 8 and pinion I9 secured to the shaft 66. Since the sprockets 68 are formed as a unit with the hub and the teeth subsequently milled, such teeth are inperfect alignment. When any adjustment of the sprocket chains is to be made the bolt II is loosened and therhub moved to the desired degree after which the bolt isagain tightened. From this construction it is apparent that both sprockets 68 are adjustedinunison by a single adjustment of the hub on the shaft. The upper sprockets on the shaft I2 are independently adjustable as has been heretofore the practice, said sprockets having collars and set screws II which hold the sprockets in proper position on the shaft. After these sprockets have been once aligned they need not be changed when adjustment of the hub 61 is made.

important that it may be made with convenience andcertainty. The construction of the hub 6'5 with the sprocketsr68 integral therewith makes this result easy of attainment.

In my application Serial No. 619,173 filed June 25, 1932, I have shown and described a bag machine in which the slack, which it is necessary to form in the bag tube before it is severed, is produced by the action of the striker barv and not by the action of the pinch bars as has been heretofore the custom. In the present construction the same timing of the parts is utilized and which timing is indicated by the position of the striker bar I4 in respect of the pinch bar 41 (Fig. 1). 10

The pinch bar has not yet engaged the bag tube but the striker bar is just about to engage the bag tube. The slack in the tube is created entirely by the striker bar, the pinch bar engaging the bag tube just at the moment when the bag 15 is severed by the knife edges 59 and I6 which sever respectively the lower and upper bag walls.- After a bag length has been severed from the tube and'the bag bottom formed the bag passes on to delivering mechanism which may be of the .20

usual and well known construction and which is merely indicated more or less diagrammatically in the drawings and need not be specifically de scribed.

At the formation of each bag tube and at 25 the moment of severance thereof the pinch bar 4! engages the tube and creates the necessary tautness which enables the striker bar'to effect severance. During the remaining portion of the cycle of rotation of the pinch bar shaft 30 54, however, the pinch bar'4'I does not engage the tube such action resulting in more or less tendency of the shaft 54 to vibrate .due to the rapid succession of contacts of the bar 41 with the bag tube. causing any bending of the shaft 54 I provide a central support for this shaft as illustrated in Figure 3.

Between the standards I0 is av flat bar IIB secured to the standards by screws IZIItapped 4 'into the standards.

ries a cupped bearing I26 engaging the shaft 45 54 in the manner shown in Figures 1 and 3. The shaft 54 and the bar 41 are suitably recessed to receive the bearing and screws I21 act to clamp the rod I24 in proper position.

What I claim is:-

1. In a bag machine the combination with side frame members, bag tube forming ,mech-' anism including feed rollers and upper and lower pinch bar shafts between which the bag tube is fed prior to severance said shafts being jour- 55 nalled in said side frame members, of means for preventing transverse separation of said pinch" bar shafts during the severing operation.

2. In a bag machine, the combination with bag tube forming mechanism including feed roll- 60 ers and upper and lower pinch bar shafts, of striker bar mechanism including a shaft driven in timed relationwith said pinch bar shafts, 'a.

hub on said driven shaft, means for holding said hub in various positions of adjustment about 65 bag tube forming mechanism including feed rollers and upper and lower pinch bar shafts, of striker bar mechanisms including a shaft driven in timed relation with said pinch bar shafts, a

hub on said driven shaft, means for holding said hub in various positions of adjustment about said To prevent such vibrations from 35 shaft, aligned sprockets rigid with said hub and striker bar supporting chains engaging said sprockets.

4. In a bag machine the combination with side frame members, bag tube forming mechanism including feed rollers and upper and lower pinch bar shafts between which the bag tube is fed prior to severance, said shafts being journalled in said side frame members, of means for supporting the upper pinch bar shaft against upward thrusts.

GEORGE W. POPPE. 

